The objective of this proposed program is the creation of a child injury data base for use in biomechanics research. The focus of this study is the definition of injuries observed in young children who have been involved in automobile accidents while restrained by child restraint systems. A six month retrospective study will be performed with the aim of correlating the reported injuries of child accident victims, the involved child restraint device, the physical properties of the injured child, and the particular accident characteristics. This study will include data from the United States Department of Transportation National Accident Sampling System (NASS), and Fatal Accident Reporting System (FARS) files, data collected by the Canadian Ministry of Transport, accident reports collected by various child restraint manufacturers, and the injury/police report correlated data in the western New York area. The retrospective study will be supplemented with in-depth investigations of relevant accidents which occur during the Phase I time frame. The results of this study will lead to increased understanding of child impact injury mechanisms, better definition of child impact tolerance levels, and the development of more effective child restraint systems, child size test dummies possessing higher levels of biofidelity, and more realistic performance evaluation criteria for child protection devices.